Tool Palette - Can't add new block to palette

Hello,

I'm currently updating a Tool Palette with new blocks. It was all going well until I tried to make changes on the path of the TP (options > files > tool palettes) to the companys network. The DWG containing the blocks, which I am updating, was already in the network. My problem is that I created some more blocks but when I highlight any block in the file and try to drag it to the palette to add it there, it won't work as it was. I tried setting the TP path to the old TP file path but without any luck.

 I appreciatte any help !

Thanks.